I`ve used Redline MTL on my last 3 cars, i love that oil. It made gearchanges noticeable better.
Im using MTL in my tiburon back when they specced 75w90 and it has worked great.
However here is the
@MolaKule list of dedicated MTFs. I have also used mt85 and it worked very well too so to stay in spec that's what I would go with.
As you can see in here the valvoline synchromesh is not quite what you're looking for and on par with the 75w80 fluids.
A. These MTF fluids are closest to a Kinematic Viscosity of 6.X cSt@100C (About the same viscosity as a Dexron VI) and SAE 70 or so:
1. Castrol Syntrans FE 75W,
2. BMW (Pentosin) MTF-LT-3,
3. Honda MTII or MTF 2.
4. Ford FML-XT-11-QDC
5. Volvo Manual Transmission Fluid (6.4 cSt) [Recommended for: type M65 5-speed with 6-cyl. engine, M66, MTX75 and MMT6 and of the type M56, M58 and M59 from and including model year 1996. Meets Ford specification WSSM2C200-D2]
6. Redline MT-LV SAE Viscosity Grade 70W/75W Vis
6.5cst@100°C
B. The next higher viscosity MTF would be the 7.0 to 7.6 cSt@100C versions (SAE 70W75) (About the same viscosity as the original DexronIII/Merc)
1. Royal Purple's Synchromax
2. Ravenol MTF-2
3. Honda MTF
4. VW part number G052512A2
5. GM Manual Transmission and Transfer Case Fluid
6. BMW (Pentosin MTF 2) MTF-LT-1, 2 ,3
7. Tutelo (Petronus, Italy, Product Code 1402)
8. Pentosin Pro Gear 70W75 (Australia)
9. Pentosin FFL-4
10. Redline Power Steering Fluid
11. RAVENOL STF
Note: C, D and E are often considered popularly as “synchromesh” fluids.
C. The next higher viscosity MTF group is in the 8.0 cSt to 8.9 cSt Range would be:
- Castrol Syntrans V FE (8.0cSt)
- Redline DCTF Dual Clutch Transmission Fluid (8.1 cSt)
- BG Synchroshift II (8.2 cSt)
- Valvoline MTF Part Number 811095 8.8 cSt
- RAVENOL PSA (8.9 cSt)
D. The next higher viscosity MTF group in the 9.0 to 9.5 cSt range is (SAE 75W80):
- Mopar Type MS-9417 MTL 9.0 cSt
- Pennzoil Synchromesh 9.0 cSt
- RAVENOL SSG 9.5 cSt
E. The next group of MTF’s are in the 9.6 to 10.X cSt range (SAE 75W80):
1. Redline MTL 75W80
2. Amsoil MTF (9.7 cSt)
3. GM Synchromesh’s
4. Volvo MTF 645
5. Fuchs TITAN SINTOFLUID SAE 75W-80 synthetic MTF (Carries a GL-5 rating as well)
6. Lodexol (Morris Lubricants) MTF
7. Motylgear 75W-80
F. The next higher viscosity MTF would be a 12.0cSt@100C and SAE 75W85:
1. Redline MT-85
G. The next higher viscosity MTFs in the 14-15 cSt (SAE 75W90) range would be:
1. Amsoil MTG
2. Redline MT-90
3. Castrol Syntrans Multivehicle 75W-90
4. Castrol Syntrans Transaxle 75w-90
5. Ford XT-75W90-QGT (Carries a GL-5 rating as well)
6. Ford MOTORCRAFT® Full Synthetic Manual Transmission Fluid XT-M5-QS
7. ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid
8. RAVENOL TSG SAE 75W-9
9. LiquiMoly 75W-90 GL4
10. Pennzoil 75W90 GL-4
11. Motul Gear 300 GL-4/GL-5 (Product Number 100118)